there are many implementation in how to check whether a String value is null and I'm really confused what to use! These are my searches so far: if(myString == null){} Objects.equals(null, myString); ObjectUtils.isEmpty(myString) myString.equals(null) myString.compareTo(null); NOTE: This is all about performance, reliable coding, fail-safe and other security purposes! Updated: myString is dynamic, what if it was null, some of the implementation above will throw NullPointerException!

Reputation: 33

Best method to check if a value of a String is null in Java

there are many implementation in how to check whether a String value is null and I'm really confused what to use!

These are my searches so far:

NOTE: This is all about performance, reliable coding, fail-safe and other security purposes!

Updated: myString is dynamic, what if it was null, some of the implementation above will throw NullPointerException!

Upvotes: 1

Reputation: 11

String results;
if(results==null ||results.length()==0) {

}

Upvotes: -1

Reputation: 28279

if(myString == null)

Easiest and right way.
Objects.equals(null, myString)

A right way, its implemention is based on 1.
ObjectUtils.isEmpty(myString)

Not sure which ObjectUtils you are working with, but it seems to check myString is empty, not null.
myString.equals(null)

This does not work when myString is null, NPE will be thrown.
myString.compareTo(null)

This does not work when myString is null, NPE will be thrown.

Upvotes: 5

Reputation: 59960

Another Option if you are using Java 8 you can use Optional::ofNullable

Optional.ofNullable(myString).isPresent()// true if not null, false if null

You can even use :

Optional.ofNullable(myString)
        .orElseThrow(() -> new Exception("If null throw an exception"));

There are many Options, just read the documentation

But as Mureinik mention in his answer == is enough in your case.

Upvotes: 8

Reputation: 311163

Just use a simple ==. There's no need to overcomplicate this.

Upvotes: 9